[Bug libfortran/41335] VOLATILE in Fortran does not take effect

["kargl at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #5 from kargl at gcc dot gnu dot org  2009-09-11 18:18 -------
(In reply to comment #4)
> I tested "real, volatile" and "double precision, volatile" with fixed form and
> free form and "real*" works, "double*" - not.
> 
> So it is not a question of a source form now, but rather why "double precision,
> volatile :: a" ignores volatile attribute?
> 

Can you define what you mean by works?  The intermediate code that
-fdump-tree-original produces is identical for the REAL(4) and REAL(8)
with the obvious difference of the kind type parameter.

program VolatileTest
  double precision, volatile :: a
  double precision :: uA, uB, b, c
  real, volatile :: ra
  real :: ruA, ruB, rb, rc
  read(*,*) uA, uB, ruA, ruB
  a = uA * uA
  b = uB * uB
  c = a - b
  ra = ruA * ruA
  rb = ruB * ruB
  rc = ra - rb
  print *, c, rb
end program VolatileTest


gives


volatiletest ()
{
  volatile real(kind=8) a;
  real(kind=8) b;
  real(kind=8) c;
  volatile real(kind=4) ra;
  real(kind=4) rb;
  real(kind=4) rc;
  real(kind=4) rua;
  real(kind=4) rub;
  real(kind=8) ua;
  real(kind=8) ub;

  {
    struct __st_parameter_dt dt_parm.0;

    dt_parm.0.common.filename = &"dd.f90"[1]{lb: 1 sz: 1};
    dt_parm.0.common.line = 6;
    dt_parm.0.common.flags = 128;
    dt_parm.0.common.unit = 5;
    _gfortran_st_read (&dt_parm.0);
    _gfortran_transfer_real (&dt_parm.0, &ua, 8);
    _gfortran_transfer_real (&dt_parm.0, &ub, 8);
    _gfortran_transfer_real (&dt_parm.0, &rua, 4);
    _gfortran_transfer_real (&dt_parm.0, &rub, 4);
    _gfortran_st_read_done (&dt_parm.0);
  }
  a = (volatile real(kind=8)) (ua * ua);
  b = (real(kind=8)) (ub * ub);
  c = (real(kind=8)) (a - b);
  ra = (volatile real(kind=4)) (rua * rua);
  rb = (real(kind=4)) (rub * rub);
  rc = (real(kind=4)) (ra - rb);


  {
    struct __st_parameter_dt dt_parm.1;

    dt_parm.1.common.filename = &"dd.f90"[1]{lb: 1 sz: 1};
    dt_parm.1.common.line = 13;
    dt_parm.1.common.flags = 128;
    dt_parm.1.common.unit = 6;
    _gfortran_st_write (&dt_parm.1);
    _gfortran_transfer_real (&dt_parm.1, &c, 8);
    _gfortran_transfer_real (&dt_parm.1, &rb, 4);
    _gfortran_st_write_done (&dt_parm.1);
  }
}


main (integer(kind=4) argc, character(kind=1) * * argv)
{
  static integer(kind=4) options.2[8] = {68, 255, 0, 0, 0, 1, 0, 1};

  _gfortran_set_args (argc, argv);
  _gfortran_set_options (8, &options.2[0]);
  volatiletest ();
  return 0;
}


-- 

kargl at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41335